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// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
#if !NO_PERF
using System;
using System.Collections.Generic;
using System.Reactive.Linq.ObservableImpl;
namespace System.Reactive
{
internal static class Helpers
{
public static int? GetLength<T>(IEnumerable<T> source)
{
var array = source as T[];
if (array != null)
return array.Length;
var list = source as IList<T>;
if (list != null)
return list.Count;
return null;
}
public static IObservable<T> Unpack<T>(IObservable<T> source)
{
var hasOpt = default(bool);
do
{
hasOpt = false;
var eval = source as IEvaluatableObservable<T>;
if (eval != null)
{
source = eval.Eval();
hasOpt = true;
}
} while (hasOpt);
return source;
}
}
}
#endif
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